Aplousobranchia

Thirteen families, 59 genera and 1501 species worldwide, with nine families, 24 genera and 95 species native to southern African seas, and a further two species that are naturalised in the region.

Family: Clavelinidae

Two genera and 48 species worldwide, with one genus, Clavelina, native to southern African seas, where it is represented by three native species and one  that is naturalised.

Family: Didemnidae

Nine genera and about 586 species worldwide, with seven genera and 28 species native to southern African seas and a further species that is naturalised in the region. 

Family: Holozoidae

Nine genera and 102 species worldwide, with four genera and eight species native to southern African seas.

Family: Polycitoridae

Nine genera and 190 species worldwide, with four genera and 17 species native to southern African seas.

Family: Polyclinidae

Ten genera and 428 species worldwide, with four genera and 28 species native to southern African seas.

Family: Pseudodistomidae

Three genera and 32 species worldwide. One species, Pseudodistoma africanum (Strawberries), is native to the southern African seas.

Family: Pycnoclavellidae

Two genera and 27 species worldwide, with one genus in southern African seas, Pycnoclavella, represented by six species.

Family: Ritterellidae

Three genera and 24 species worldwide, with one genus in southern African seas, Ritterella, represented  by three species.

Family: Stomozoidae

One genus, Stomozoa containing five species. Represented in southern African seas by one species, Stomozoa roseola.

Phlebobranchia

Nine families, 40 genera and 328 species worldwide, with four familes, five genera and 15 species native to southern African seas and a further family, genus and species naturalised in the region.

Family: Agneziidae

Five genera and 32 species worldwide, with one genus in southern African seas, Agnezia, represented by two species.

Family: Ascidiidae

Five genera and 150 species worldwide, with one genus and eight species native to southern African seas, and a further genus and species that is naturalised in the region.

Family: Cionidae

Three genera and 17 species worldwide. No native species in southern African seas but Ciona intestinalis (Sea vase, Vase tunicate) has become naturalised in the region.

Family: Corellidae

Eleven genera and 41 species worldwide, with two genera and two species native to southern African seas.

Family: Perophoridae

Two genera and 50 species worldwide, with one genus in southern Africa, Ecteinascidia, represented by three species.

Stolidobranchia 

Four families, 68 genera and 1023 species worldwide, with three families, 24 genera and 66 species native to southern African seas and a further four species that are naturalised in the region.

Family: Molgulidae

Thirteen genera and 226 species worldwide, with three genera and eight species native to southern African seas.

Family: Pyuridae

Seventeen genera and 246 species worldwide, with six genera and 16 species native to southern African seas, and a further species that is naturalised in the region.

Family: Styelidae

Thirty-six genera and 538 species worldwide, with 15 genera and 42 species native to southern African seas, and a further three species that are naturalised in the region.